Design of Long-Wave Fully Polarized HgCdTe Photodetector Based on Silicon Metasurface

Area of Science:

• Optoelectronics
• Nanophotonics
• Metamaterials

Background:

• Polarization-sensitive photodetection is crucial for optical systems.
• Simultaneous detection of circularly polarized (CP) and linearly polarized (LP) light with compact devices is challenging.

Purpose of the Study:

• To demonstrate a silicon metasurface-integrated MCT photodetector for simultaneous CP and LP light detection.
• To achieve high-fidelity polarization recognition using a single ultrathin platform.

Main Methods:

• Utilized COMSOL 5.6 software for device simulation.
• Designed a silicon metasurface with orientation-specific linear gratings for LP detection.
• Incorporated chiral symmetric silicon nanostructures for CP discrimination.

Main Results:

• Achieved simultaneous resolution of both CP and LP light signals.
• Demonstrated direct CP discrimination with a 30 dB extinction ratio.
• Enabled superior polarization reconstruction through grating selectivity and chiral near-field enhancement.

Conclusions:

• Established a new paradigm for miniaturized, high-performance polarization optics.
• The proposed fabrication-simplified process eliminates complex alignment.
• Potential applications include polarization imaging, quantum communication, and hyperspectral sensing.